Talk:Standard solar model

Erroneous citation needed tag

Asking for a citation in the scientific literature for something that is blatantly obvious is asking too much. There is no justification for the "citation needed" tag on the statement "Thus the assumption of steady state is a very good approximation." A million years at more or less the same state is about as close to steady state as it gets. Eleven billion years? Please. That's steady state.

On the other hand, the equation that follows that erroneous "citation needed" is not marked with a "citation needed" tag. That equation is where a citation is needed.

Opening heading

I really think that this article does not describe the topic "Standard Solar Model". It has a lead section about the sun and the rest of the article is about neutrinos and the so-called neutrino problem for the sun. A complete rewrite (or renaming) is called for. Regards, --Sir48 (talk) 15:38, 4 June 2008 (UTC)

wrong units, not solar model

First off, I second the comment that this article is unfinished. An article on the standard solar model, including the neutrinos as well as other stuff, IS needed. As for the neutrinos, I'd like to know the fraction of the solar power that is carried off with them -- I suppose can be calculated from the graph. Secondly, there is an omission in the units on the y-axis of the neutrino graph. The neutrino "flux" should really be flux-energy density with the units of cm^-2sec^-1MeV^-1. Yes, I understand it was taken from a source, well there is an omission there, so what should be done, it doesn't make sense this way?(e.g., TOTAL solar neutrino flux on earth should be 6E+10/cm²/sec, i.e., the integration over all the energies on the graph).24.58.175.197 (talk) 19:46, 1 November 2008 (UTC)john wilkinson

No links to stellar structure or stellar nucleosynthesis

Stellar structure defines and describes all the equations of stellar structure in the spherically-symmetric quasi-static model, describing energy transport much more clearly than in the present article, yet is not linked to. Similarly, stellar nucleosynthesis and its daughter articles (the relevant ones for the Sun being the p-p chain and CNO cycle) does a much better job than the present article at describing the fusion processes. My reference Dale A. Ostlie et al's "An intro to modern stellar astrophysics" has a chapter on the Solar interior which provides graphs of the interior composition of the Sun taken from Bahcall et al Ap. J., 555, 990, 2001. If any of these graphs can be used to illustrate the article, and I don't have experience of this myself, that would surely be of interest for the article. Puzl bustr (talk) 15:22, 4 November 2009 (UTC)

The ADSABS link is Solar Models: Current Epoch and Time Dependences, Neutrinos, and Helioseismological Properties.Puzl bustr (talk) 15:26, 4 November 2009 (UTC)

The article's external link What is a Standard Solar Model, though it should not be copied for copyright reasons, presents the topic in clear language in my POV, and could be paraphrased to the benefit of the current article. Puzl bustr (talk) 15:34, 4 November 2009 (UTC)

Re-wrote introduction

I went ahead and re-wrote the introduction and added my reference for evolution and added the wikilinks I mentioned above. I haven't changed anything from the equation of state section on, but I intend to re-write that too. Comments on what I've done so far welcome. Puzl bustr (talk) 16:48, 4 November 2009 (UTC)

Finished first re-write

Re-wrote up to, but not including, the neutrino production section. Included a description of how the boundary conditions are applied, how the zero age model is generated, and a brief description of numerical integration. Hope this gives the flavour of what is going on, and consolidates the earlier material in (I hope) a coherent way. The material on neutrinos also needs re-writing. Puzl bustr (talk) 23:45, 4 November 2009 (UTC)

Entropy section

The entropy section seems to be taken from the Guenther external link. It states that: "The entropy term is the sole term in the basic stellar evolution equations that includes time explicitly." However, this statement is directly contradicted by the reference Clayton 1983 Principles of Stellar Evolution and Nucleosynthesis, which points out that the nuclear reactions change the composition over time, as would seem to be explicitly indicated by the equation for $\epsilon$ including a time derivative. In fact, Clayton suggests that for a star on the main sequence, or at least burning stably in the core, this entropy term is so small as to be neglected. In fact, there is actually also a time dependence in the equation of hydrostatic equilibrium, where instead of the difference between the pressure gradient and density time gravity being zero, it is the second deriv. of radius wrt. time. Again, for stars burning the core fuel stably this time dependence term is so small as to be neglected. This contradiction, and my inability to find a reference describing how the entropy term might be calculated, leaves me thinking an expert is required to sort this out. The Clayton reference suggests that the stellar structure equations be recast with mass as the independent variable instead of time, and sketches an approximation for how the mass fractions of nuclear species being changed by the fusion processes vary with time, explicitly noting that this approximation would not hold if radius were the indep. var. I don't want to go through a derivation of two sets of stellar equations! My POV is that Clayton is more likely to be correct, since the entropy term is at least related to gravitational contraction, according to the Ostlie reference, though Clayton objects to this terminology for some reason.Puzl bustr (talk) 22:36, 5 November 2009 (UTC)

Finished re-write

I took the decision to remove the section on entropy, which didn't, in my POV, add any explanatory power to the article and was disputed by some references. Instead I decided to give a simplified (hopefully) coherent picture of how the modelling works without repeating all the information about stellar structure equations from the stellar structure article, mainly in the evolution of the sun section. I cleaned up the later sections.

I need to rest (I have RSI) now but will then return to add some references. I should add a section on convection which mentions mixing length without reproducing too much of the dicussion in stellar structure. Puzl bustr (talk) 12:00, 6 November 2009 (UTC)

There also needs to be a section on helioseismology. Puzl bustr (talk) 12:03, 6 November 2009 (UTC)

A further re-write with additional references

Added refs for (meteoritic) age of sun and diffusion effect on photospheric abundances. Added details of energy transport equations with mixing length reference. Added section on helioseismology (which gives an alternative seismic age of the Sun). Added section on energy transport, to indicate which processes of energy transport dominate in different zones within the Sun, and gave the equations used in models with all the variables defined. Hopefully the references are satisfactory now. Puzl bustr (talk) 21:54, 7 November 2009 (UTC)

There is still a need for a section describing how the equations of state are calculated, for example the pressure and the opacity. Puzl bustr (talk) 22:12, 7 November 2009 (UTC)

Added section on equation of state

Added this section as advertised, but most of the detail I put in stellar structure to avoid duplication. Corrected the discussion of convection to deal with the adiabatic and non-adiabatic cases (my bad!). Again I added more info about this to stellar structure. Here I just gave a summary with reference to stellar structure and put in example info relating to the Sun. The helioseismology section, or perhaps the helioseismology article, could do with some expansion, but my re-write is essentially complete now. Puzl bustr (talk) 17:48, 8 November 2009 (UTC)

Added section on simulations of near-surface convection

This is important to show that it is possible to go beyond a parametrised model, with enough computer time and detailed physics. This makes the SSM a proper scientific theory, making predictions independent of observations. Puzl bustr (talk) 14:14, 29 November 2009 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: page moved. Vegaswikian (talk) 06:37, 28 October 2011 (UTC)

---

Standard Solar Model → Standard solar model –

Per WP:CAPS ("Wikipedia avoids unnecessary capitalization") and WP:TITLE, this is a generic, common term, not a propriety or commercial term, so the article title should be downcased. Lowercase will match the formatting of related article titles. Tony (talk) 13:30, 21 October 2011 (UTC)

• Comment it appears that "Solar" should be capitalized since it refers to the Sun of our Solar System, and not any sun of any solar system. 65.94.77.11 (talk) 05:21, 22 October 2011 (UTC)

It did flicker through my mind. I've asked Noetica and Dicklyon for opinions. Tony (talk) 07:23, 22 October 2011 (UTC)

• Support. First let's note that nothing about capitalising "solar" itself affects the capitalising of "model" (or "standard", for that matter). Set that aside as a separate question for now. As for "solar", it is aptly used with lower case in these articles (shown with "s" for clarity):

solar mass
solar calendar
solar eclipse (cf. lunar eclipse also)
solar energy (see many related uses of "solar" there)
solar constant (see uses of this, and more, at sunlight: redirected from solar radiation)

Well-founded precedent seems to support lower case here. The solar model in question is no more essentially about "Sol" (the Sun) than, say, "solar calendar" or "solar mass" are. All are generalisable beyond the case of Sol to the case of any similar star; and indeed the present article refers to general stellar parameters and theory, in this heading for example: "Numerical modelling of the stellar structure equations". I therefore favour a default lower-casing of "solar" in the title.

Now we pick up the issue of "model". This has no independent claim to upper case; it could only be capped if "standard" and "solar" are to be capped along with it (in the text of the article). From the sample I give above, I see no warrant for that. The entity named is less known than "Solar System", and is not a spatiotemporally located astronomical feature. It is more a theoretical construct like "solar calendar".

I therefore vote in support of the move, in accord with the first principle given at WP:MOSCAPS, which is to avoid unnecessary capitalisation See also the lower-case treatment of scientific laws, at the same MOS page. Nothing in the article or its surrounds argues for the necessity or even the desirability of capitals here; so make it Standard solar model, and "standard solar model" throughout the text.

Noetica^Tea? 08:05, 22 October 2011 (UTC)

• Support – a no-brainer, since there's little suggestion in the literature for capitalization of any of the words. Dicklyon (talk) 17:06, 22 October 2011 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

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